The present invention relates to a tensioning device constructed especially as a double eccentric tensioning device for a traction means drive, which, in the installed state, guarantees sufficient pretensioning of a traction means of the traction means drive.
From DE 40 33 777 A1 a tensioning device constructed as a double eccentric tensioning device is known. This tensioning device comprises an adjustment eccentric, which is provided for receiving an attachment screw with an eccentrically positioned bore. By means of the attachment screw, the tensioning device is mounted on a housing, especially a housing of the internal combustion engine. A work or operating eccentric surrounding the adjustment eccentric is supported so that it can pivot by means of a plain or slide bearing on the adjustment eccentric. A rolling bearing comprising a rolling bearing outer ring, which is constructed so that this simultaneously provides the function of a running disk, by means of which the tensioning device is supported against a traction means, especially a belt, in the operating state. For achieving a firm contact of the running disk on the traction means, between the base plate and the operating eccentric there is a torsion spring, whereby a pivoting moment is applied to the operating eccentric and in this way the running disk is forced against the traction means, especially a toothed belt. For mounting the traction means, this known tensioning device requires manual rotation of the operating eccentric into an end position, because a placement of the traction means is possible only in this way.